Disposable cassette

ABSTRACT

The invention relates to a disposable cassette as a replaceable component of an analysis instrument comprising fluid paths integrated in the cassette. In accordance with the invention, at least one container with a liquid, for example a calibration fluid, is integrated in a liquid-tight manner in the disposable cassette. An integrated spike is provided in the disposable cassette, for example as a pivotable rocker hook, via which the pouch can be opened so that the liquid can be guided into the fluid paths of the disposable cassette.

The invention relates to a disposable cassette in accordance with the preamble of claim 1.

Disposable plastic articles with fluid carrying passages are frequently used in medical equipment. Corresponding cassette systems have proven their worth here as alternatives to conventional hose systems. The corresponding fluid paths are formed in these cassette systems. The fluid flowing through the fluid paths is introduced by means of corresponding actuators. For instance, valves are, for example, used via which the fluid paths are switched open or are closed. On the other hand, pumps for the transport of the fluid are integrated in such cassette systems. In the field of medical application, disposable cassette systems are already known in which a rigid part is provided in which passages are let into chambers. This rigid part is covered by a continuously flexible film. In accordance with DE 102 39 597, this flexible film is formed by flexibly formed regions in the rigid part, with the rigid and flexible regions being able to be manufactured in one piece using a two-component injection moulding technology.

The aforesaid cassette systems can also be used to advantage in the field of analysis technology.

The liquids required for the analysis, for example calibration fluid, have to be connected in accordance with the prior art by means of expensive access adapters provided especially for this purpose for sterile connection. Such access adapters result, for example, from U.S. Pat. No. 6,016,683, U.S. Pat. No. 6,136,607 A or EP 1 243 336 A2.

It is the object of the invention to provide a disposable cassette in which the sterile access to a liquid, for example to the calibration fluid, is made possible in a simple manner without special access adapters having to be provided for this purpose.

The object is solved in accordance with the invention by the combination of the features of claim 1. Accordingly, at least one container with a liquid, for example the calibration fluid, is integrated in a liquid-tight manner into the disposable cassette. At the same time, a spike which is preferably made as a pivotable rocker hook, is provided at the disposable cassette and the pouch can be opened via it such that the liquid can be guided into the fluid paths of the disposable cassette.

Particular advantages of the invention result from the dependent claims following the main claim.

Accordingly, the region of the spike in the disposable cassette can be covered by a film and the region of the spike is preferably surrounded in ring-like manner by a sealing web while leaving a merging fluid path free. It is thus ensured after the cutting of the one film wall by means of the spike that the discharged liquid is guided into the merging fluid path without leakage.

The container can preferably be made as a pouch from aluminium multilayer film.

The pouch can have at least one deep-drawn spherical arrangement in the film wall in the region of the rocker hook on the side facing away from the rocker hook, said spherical arrangement ensuring that the film in which this spherical arrangement is provided is not damaged on the pivoting in of the rocker hook. Any other design of a spike can serve to open the film wall instead of the previously described rocker hook which can be pivoted in.

The rocker hook is preferably made in one piece with the disposable cassette. The disposable cassette is an injection moulded plastic part and the rocker hook can be moulded pivotably to this injection moulded plastic part such that it can be pivoted by means of a machine pusher such that it cuts open a side of the pouch correspondingly inserted in the disposable cassette. The rocker hook can advantageously have a fluid passage in the form of a channel such that a possible occlusion of the free flow is prevented.

In accordance with a further aspect, the invention relates to a method for the provision of a sterile access for a pouch inserted into a disposable cassette in accordance with the present invention. Accordingly, the pouch filled with liquid is connected to the disposable cassette in a completely sealed manner. A wall of the pouch is cut open by means of the associated rocker hook to open the pouch access without damaging the opposite wall of the pouch formed as a deep-drawn spherical arrangement.

The system has the advantage that the pouch is completely sealed before the corresponding cutting open by the rocker hook and has no openings in the film wall. The storage capability of a sensitive liquid such as a calibration fluid is improved in this manner.

Details and advantages of the invention result from an embodiment shown in the drawing. There are shown:

FIG. 1: the plan view of a disposable cassette in accordance with an embodiment of the invention;

FIG. 2: a section corresponding to the section line II-II through FIG. 1;

FIG. 3: a section corresponding to the section line III-III through FIG. 1;

FIG. 4: a pouch for insertion into a disposable cassette in accordance with FIG. 1 in plan view; and

FIG. 5: a section corresponding to the section line V-V through FIG. 4.

In the disposable cassette 10 shown in FIGS. 1 and 2, a passage structure 14 is formed in a first part 12, which is made as an injection moulded plastic part, for the purpose of the fluid guidance and is covered in a known manner by means of flexible elastomer material in accordance with DE 102 39 597 of the same applicant. The injection moulded plastic part 12 has a shell-like recessed region 16 in which there lie 3 pouches with calibration fluid 18 and one waste pouch 20. The pouches 18 which are provided with calibration fluid and which are closed in the unused state of the disposable cassette 10 are connected to passages 14 via input regions which are to be opened directly. The waste pouch 20 is likewise connected to the passages at 28. A series of actuators is present in the passage system 14 in the form of valves not shown in more detail here or in the form of a pump 32. Respective flexible plastic layers, which can be actuated via pushers on the machine side not shown in more detail here, are provided in the valves or in the pump 32. Reference can be made to DE 102 39 597 for the more detailed function. Liquid can be directly transported in the passage system 14 by a corresponding control of the valves 30 or of the pump 32.

A sample port 34 is present for the inlet of a sample liquid, for example whole blood, serum or urine.

The sample port 34 can be closed via a slider 40 which cooperates with a plastic flap 38. The whole sample port can be flushed by introducing a flushing liquid after introducing the sample and closing the plastic flap 38.

An old blood sample or an old calibration solution can be replaced by fresh calibration solution by this flushing. The disposable cassette 10 represented in its design and in its function is inserted into the analysis instrument not shown in any more detail here and is pressed tight. Usually, the disposable cassettes are designed for a period of use of 24 hours or of approximately 30 measurements. The required calibration solution is taken from the corresponding pouches 18. These pouches are integrated into the disposable cassette in a liquid tight manner prior to the measurement, i.e. they lie on top of one another in the manner shown in FIG. 2 in the region 16 of the injection moulded plastic part 12 recessed in the form of a shell. The pouches 18 are firmly connected to the injection moulded plastic part 12 in each case in the region 50, 52 or 54.

The design of a pouch 18 results from FIGS. 4 and 5. The pouch 18 consists in each case of an upper and a lower layer of an aluminium multilayer film 56 or 58 which are welded together along a weld line 60 such that they leave an opening region 62 free. The opening region is defined by two weld seams 64 which initially extend parallel to one another and move away from one another toward the outer end of the pouch 18 as conical weld lines 66 while forming a conical opening region 68. One half of the film has a deep-drawn spherical arrangement 68. In addition, a region of deep-drawn passages 70 which extend parallel to one another and which bring about a reinforcement of the pouch and thus protection against kinking is realised in the opening region 62.

In FIG. 4, the pouch 18 is shown during filling. After filling and after welding the opening closed, the pouch is firmly connected, preferably adhesively bonded, to the first part 12 of the disposable cassette 10 made as an injection moulded plastic part. In FIG. 3, a sectional representation of the region is shown in which it is shown that the pouch 18 consisting of the layers 56 and 58 is adhesively bonded to the injection moulded plastic part 12. In this process, the spherical arrangement 68 deep-drawn in the film 56 is positioned at a location in which a pivotably moulded rocker hook 72 is arranged in the region of the injection moulded plastic part 12. As can in particular be seen in FIG. 3, a sealing lip 74 is arranged around the rocker hook and is upwardly sealingly covered by means of a flexible plastic layer 76. A fluid passage 14 opens at one side.

In order to open the pouch 18, the rocker hook 72 is pivoted about an actuation pusher on the machine side, which is not shown in any more detail here, such that the sharp tip 78 of the rocker hook 72 severs or cuts open the film 58 of the pouch 18, as is shown in FIG. 3. The film 56 of the pouch 18 is not damaged due to the deep-drawn spherical arrangement 68. The calibration fluid contained inside the pouch 18 now flows through the opening created in this manner into the space surrounded in ring-shaped manner by the sealing web 74 and can thus be guided into the passage 14. A corresponding vacuum in the passage system 14 can be built up via the pump 32.

In this manner, a sterile access to a film pouch can be created in a very simple manner. The invention disclosed here with reference to a disposable cassette system which is proposed as a replaceable component of an analysis instrument can also be used within the framework of another system in which it is a question of the problem of a sterile access to a liquid filled in a film pouch without leaving the framework of the invention, 

1: A disposable cassette comprising fluid paths integrated in the cassette, characterised in that at least one container with a liquid, for example a calibration fluid, is integrated in the disposable cassette in a liquid-tight manner and in that an integrated spike is provided at the disposable cassette and the container can be opened via it such that the liquid can be guided into the fluid paths of the disposable cassette. 2: A disposable cassette in accordance with claim 1, wherein the region of the rocker hook in the disposable cassette is covered by a film and in that the region of the spike is surrounded in ring-shaped manner by a sealing web while leaving free a merging fluid path. 3: A disposable cassette in accordance with claim 1, wherein the container is a flexible pouch of an aluminium multilayer film. 4: A disposable cassette in accordance with claim 1, wherein the integrated spike consists of a rocker hook hinged to the disposable cassette. 5: A disposable cassette in accordance with claim 4, wherein the rocker hook has a fluid passage in the form of a channel such that a possible occlusion of the free flow is prevented. 6: A disposable cassette in accordance with claim 1, wherein the container has a deep-drawn spherical arrangement in the film wall in the region of the spike at the side facing away from the spike. 7: A disposable cassette in accordance with claim 1, wherein the at least one spike is made in one piece with the disposable cassette. 8: A disposable cassette in accordance with claim 1, wherein the disposable cassette is a replaceable component of an analysis instrument. 9: A method of providing a sterile access for a container inserted into a disposable cassette in accordance with claim 1, characterised in that the container filled with liquid is connected to the disposable cassette in a completely sealed manner and in that a wall of the pouch is cut open by means of the associated spike to open the container access without damaging the opposite wall of the pouch formed as a deep-drawn spherical arrangement. 